openapi.yaml

openapi: 3.0.0
info:
  title: BACnet MQTT Gateway API
  version: 1.6.0
  description: API for managing and interacting with the BACnet MQTT Gateway, including runtime health for production deployments.

servers:
  - url: http://localhost:{port} 
    description: Local development server
    variables:
      port:
        default: '8082' 
        description: Server port

components:
  schemas:
    DeviceScanRequest:
      type: object
      properties:
        deviceId:
          type: string
          description: The BACnet device ID (as configured in devices/*.json or discovered).
          example: "114"
        address:
          type: string
          description: The IP address of the BACnet device.
          example: "192.168.1.101"
    DeviceConfigPolling:
      type: object
      properties:
        class:
          type: string
          description: Polling class used by the bounded scheduler.
          enum: [fast, normal, slow]
          example: fast
        intervalMs:
          type: integer
          description: Explicit polling interval in milliseconds.
          example: 5000
        freshnessMs:
          type: integer
          description: Maximum age in milliseconds before downstream systems should treat the value as stale.
          example: 15000
        schedule:
          type: string
          description: Optional cron-style schedule expression for polling.
          example: "*/15 * * * * *"
    DeviceConfigObject:
      type: object
      properties:
        objectId:
          type: object
          properties:
            type:
              type: integer
              description: BACnet object type number.
              example: 2
            instance:
              type: integer
              description: BACnet object instance number.
              example: 202
    DeviceConfiguration:
      type: object
      properties:
        device:
          $ref: '#/components/schemas/DeviceScanRequest'
        polling:
          $ref: '#/components/schemas/DeviceConfigPolling'
        objects:
          type: array
          items:
            $ref: '#/components/schemas/DeviceConfigObject'
    BacnetObjectResponse:
      type: object
      properties:
        objectId:
          type: object
          properties:
            type: 
              type: integer
            instance:
              type: integer
        name:
          type: string
          nullable: true
        description:
          type: string
          nullable: true
    WritePropertyRequest:
      type: object
      required:
        - deviceId
        - objectType
        - objectInstance
        - propertyId
        - value
      properties:
        deviceId:
          type: string
          description: The configured deviceId (key from deviceConfigs map).
          example: "114"
        objectType:
          type: integer
          description: BACnet object type.
        objectInstance:
          type: integer
          description: BACnet object instance.
        propertyId:
          type: integer
          description: BACnet property ID to write.
        value:
          type: object 
          description: The value to write. Can be string, number, boolean.
        priority:
          type: integer
          format: int32
          minimum: 1
          maximum: 16
          nullable: true
          description: BACnet write priority (1-16).
        bacnetApplicationTag:
          type: integer
          format: int32
          nullable: true
          description: BACnet Application Tag (from bacnet.enum.ApplicationTags) to specify value type.
    ErrorResponse:
      type: object
      properties:
        status:
          type: string
          example: error
        message:
          type: string
    SuccessResponse:
      type: object
      properties:
        status:
          type: string
          example: success
        message:
          type: string
        response: 
          type: object 

paths:
  /api/bacnet/scan:
    put:
      summary: Scan for BACnet devices
      description: Initiates a BACnet 'Who-Is' broadcast to discover devices on the network. The server listens for responses for a fixed duration (e.g., 5 seconds).
      responses:
        '200':
          description: An array of discovered BACnet devices.
          content:
            application/json:
              schema:
                type: array
                items:
                  type: object 
                  properties:
                    address:
                      type: string
                    deviceId:
                      type: integer
        '500':
          description: Internal server error.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'

  /api/bacnet/{deviceId}/objects:
    put:
      summary: Scan a specific BACnet device for its objects
      parameters:
        - name: deviceId
          in: path
          required: true
          description: The ID of the BACnet device to scan (must match a configured deviceId or one from discovery).
          schema:
            type: string
      requestBody:
        description: Device information, typically its IP address and BACnet deviceId.
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/DeviceScanRequest' 
      responses:
        '200':
          description: An array of BACnet objects found on the device.
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/BacnetObjectResponse'
        '400':
          description: Bad request (e.g., invalid deviceId format).
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '404':
          description: Device not found or not responding.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '500':
          description: Internal server error.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'

  /api/bacnet/{deviceId}/config:
    put:
      summary: Configure polling for a specific BACnet device
      parameters:
        - name: deviceId
          in: path
          required: true
          description: The ID of the BACnet device to configure.
          schema:
            type: string
      requestBody:
        description: Full device configuration including device info, polling schedule, and objects to poll.
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/DeviceConfiguration'
      responses:
        '200':
          description: Configuration saved and polling started/updated. Returns an empty object.
          content:
            application/json:
              schema:
                type: object
        '400':
          description: Bad request (e.g., invalid configuration format).
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '500':
          description: Internal server error.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'

  /api/bacnet/runtime:
    get:
      summary: List runtime BACnet device state
      description: Returns persisted runtime device health, circuit breaker state, and last successful poll metadata.
      responses:
        '200':
          description: Runtime state entries for configured devices.
          content:
            application/json:
              schema:
                type: array
                items:
                  type: object

  /api/bacnet/write:
    put:
      summary: Write to a BACnet object property
      requestBody:
        description: Details of the BACnet write operation.
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/WritePropertyRequest'
      responses:
        '200':
          description: Write operation successful.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SuccessResponse' 
        '400':
          description: Bad request (e.g., missing fields, invalid data types).
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '404':
          description: Device configuration not found for the given deviceId.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '500':
          description: BACnet write operation failed or internal server error.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'